Anatomical stress urinary incontinence is a condition characterized by the involuntary escape of urine through the urethra during coughing, sneezing, or other stress-producing actions. This escape does not normally occur because the urethra, in its natural position, is elevated and constricted by the fascia and muscles which suspend it from the pubic bone. Under normal conditions, this structure prevents involuntary escape of urine under conditions of increased intra-abdominal pressure.
In a patient with anatomical stress urinary incontinence, however, the urethra may have become prolapsed and unconstricted because the endopelvic fascia have been stretched or weakened. Childbirth, hysterectomy, menopause and weakened pelvic support can contribute to this weakening. With the urethra in a prolapsed condition, a sneeze or cough could cause enough pressure in the bladder to expel urine through the unconstricted urethra. Various therapies, surgical and non-surgical, have been devised to correct the condition.
The non-surgical therapies often center on the principle of introducing a substance into the urethral region which will cause a constriction. U.S. Pat. No. 4,019,498 issued to Hawtrey et al. discloses a mushroom-shaped plastic mass which, when inserted into the vagina, exerts an upward thrust against the superior wall of the vagina of sufficient magnitude to block the flow of urine through the urethra. One disadvantage of this therapy is the attendant discomfort caused by the presence of the mass in the vagina.
U.S. Pat. No. 4,686,962 issued to Haber discloses an eliptoidally-shaped containment membrane which may be hypodermically implanted between the urethra and the subcutaneous corpus spongiousum and inflated to increase tissue volume. The disadvantages of this device include the introduction of synthetic objects into the body, and possible discomfort due to the presence or shifting of the membrane.
Among the surgical therapies is a surgically implanted occlusion cup disclosed by Haber in U.S. Pat. No. 4,584,990. The cup surrounds, engages, and constricts the urethra. The disadvantages of this device are similar to those associated with the disclosures of U.S. Patent Nos. 4,019,498 and 4,686,962 as discussed above.
The traditional surgical method of correcting bladder neck prolapse is the so-called abdominal approach to retropubic surgery. In this procedure, a large incision is made in the abdomen and a suturing needle is inserted through this incision and into the vagina. The vaginal fascia is thereby sutured to supporting structures in the retropubic region. The procedure, however, has significantly high morbidity because of the presence of several large blood vessels in the operating region. It is not uncommon for the needles to slip or tear through these blood vessels and cause significant bleeding. Another disadvantage of the abdominal approach is the risk of punctures to the surgeon's finger as the finger, while inserted in the vagina, guides the suturing needle through the vaginal fascia. Such punctures could lead to transmission of hepatitis, auto-immune deficiency virus (AIDS) and other serious diseases.
U.S. Pat. No. 4,172,458 issued to Pereyra discloses a ligature carrier for use in a suspension-type of operation that is different than the abdominal approach. In the Modified Pereyra Procedure, the tissues of the elevated superior wall of the vagina on each side of the urethra are sutured to the fascia of the abdominal wall instead of the structures in the retropubic region. The Modified Pereyra Procedure involves a blind excursion of a needle proximal to the bladder. The needle is inserted through an abdominal incision into the retropubic space and from there punctures the superior wall of the vagina. Because the surgeon cannot see the tip while it is being inserted, he necessarily guides it with his fingertip. This practice leads to a high risk of incisions into the surgeon's fingers; as with the abdominal approach, hepatitis and auto-immune deficiency virus are among the more serious diseases transmittable through such incisions. There exists also the risk of puncturing the bladder during the blind excursion of the needle. In addition, sutures have been left in the bladder which can lead to incontinence from an unstable bladder and also to bladder stones. The Pereyra procedure, in addition to its various surgical risks, has an unsatisfactorily high failure rate. This results from the use of the abdominal wall fascia as supporting structures for the bladder neck. All too often, sutures placed into the fascia pull through the tissue thereby causing bladder neck descent and resulting incontinence.
Against this background, a need has been developed for a surgical device and procedure which offers decreased morbidity and greater efficacy than the modified Pereyra procedure. The procedure must offer an alternative to the blind excursion of a sharp needle in the bladder and reproductive tract region. Before the present invention, there has been no technique which offers this alternative to patients suffering from anatomical urinary stress incontinence.